The present invention relates to an electromagnetic transducer, and more particularly to an improvement in a treatment of terminals of a coil wire.
FIG. 1 shows a conventional electromagnetic transducer. In the drawing, reference numeral 6 denotes a magnetic core body, on which is mounted a coil 5. A magnet 4 is mounted on the magnetic core body 6 to surround the coil 5. Reference numeral 1 denotes a vibration plate, on the center of which is fixed a movable iron piece 2, and the periphery of the vibration plate 1 is supported by a supporting frame 3. The magnetic core body 6 is provided with a notch portion 10 and a substrate 7 is fixed on a lower surface of the magnetic core body.
FIG. 2 shows a lower plan view of the magnetic core body 6, wherein reference numerals 8 and 9 respectively denote electro-conductive patterns deposited on the substrate 7. Two terminals 11, 12 of the coil 5 are led to the lower surface of the magnetic core body 6 through the notch portion 10 and connected with the patterns 8 and 9 by welding.
In the conventional structure, the workability is inferior since it is necessary to lead the coil terminals to the rear side of the substrate to treat them.
Further the treatment of the coil terminals costs much money and time since the expensive substrate is used and it is difficult to connect them.